LimeNET Micro makes deploying wireless networks more accessible than ever before, by extending the LimeNET line of integrated hardware solutions via an ultra-low cost platform that is capable of supporting narrowband systems, such as GSM and IoT wireless standards, in a stand-alone configuration.

As with existing integrated LimeNET platforms, the new LimeNET Micro is built on the very same revolutionary field-programmable RF (FPRF) technology and features the LMS7002M transceiver at its heart. However, this highly cost-optimised, single board solution also integrates GPS for high-accuracy timing, Power-over-Ethernet (PoE), and embedded compute for fully standalone operation.

In utilising the Raspberry Pi Compute Module 3, LimeNET Micro builds on previous platforms to further democratise wireless networks in much the same way that the Raspberry Pi has democratised embedded computing.

Given its incredibly low price point and highly integrated nature, there are endless application possibilities for LimeNET Micro, ranging from cellular networks and IoT, through spectrum monitoring, test and measurement, amateur radio, and radio astronomy.

Example Use Cases

• Inexpensive enterprise and personal networks
• Rural, autonomous, and resilient networks
• Universal IoT communications hubs
• Rapid deployment infrastructure for emergency response
• Remote radio solutions for amateur radio and radio astronomy
• Integration into application-specific RF appliances
• Radio spectrum survey
• Passive wireless geolocation
• PHY and security research
• RF-aware robotics

Features & Specifications

• RF transceiver: Lime Microsystems LMS7002M
• FPGA: Intel Altera MAX 10 (10M16SAU169C8G)
  • 169-pin FBGA package
  • 16K LEs
  • 549 KB M9K memory
  • 2,368 KB user flash memory
  • 4 x fractional phase locked loops (PLLs)
  • 45 x 18x18-bit multipliers
  • 130 x general purpose input/output (GPIO)
  • Single supply voltage
  • Flash feature
  • FPGA configuration via JTAG
• GNSS module: u-blox NEO-M8Q-0-10
  • Supports BeiDou, Galileo, GLONASS, GPS / QZSS
  • Able to concurrently receive up to three GNSS
  • –167 dBm navigation sensitivity
• EEPROM memory: 2 x 128 KB for RF transceiver MCU firmware and data
• Flash memory: 1 x 4 MB flash memory for data
• General user inputs/outputs:
  • 5 x dual color (red + green) LED
  • 8 x FPGA GPIO pinheader (3.3 V)
  • 4 x FPGA switches
  • 1 x buzzer
• Connectivity:
  • 2 x coaxial RF (SMA) connectors (each can be switched between high and low frequency bands)
  • SMA connector for external clock source in
  • SMA connector for clock source out
  • SMA connector for GNSS antenna
  • Raspberry Pi Touch Screen Display Connector (ribbon cable)
  • Raspberry Pi Camera (ribbon cable)
  • HDMI connector
  • 2 x USB 2.0 ports
  • 3.5 mm audio out (Raspberry Pi Compute Module)
  • FPGA GPIO headers
  • FPGA JTAG connector
  • RJ45 connector for Ethernet and IEEE 802.3 active Power-over-Ethernet (PoE)
  • DDR2 SODIMM connector - only usable for Raspberry Pi Compute Module 3 (or Lite)
  • MicroSD slot for RPi Compute Module storage
  • Barrel connector for 12 V DC power
  • Micro-USB for USB boot of Compute Module
• Clock system:
  • 30.72 MHz OCXO: Rakon U7475LF
  • GPS disciplined for high frequency accuracy and stability
  • External clock input via SMA connector
  • Clock output via SMA connector
• Board dimensions: 125 mm x 65 mm

LimeNET Micro with Raspberry Pi Compute Module (bottom)

Block Diagram

LimeNET Micro block diagram

Raspberry Pi Compute Module (CM3) Features

A Raspberry Pi Compute Module 3 is included with every purchase of a LimeNET Micro (excluding early bird units). Raspberry Pi Compute Module 3 Lite‘s will also work with LimeNET Micro, but would require use of the separate microSD slot.

• ARM Cortex-A53 Broadcom BCM2837 SoC - quad-core, 1.2 GHz
• 1 GB RAM
• 4 GB eMMC flash

Accessories and Configurations

LimeNET Micro with Aluminum Kit

The custom plastic and aluminum case in this kit not only physically protects your LimeNET Micro, it also helps reduce noise interference. It also looks and feels smashing. The Aluminum Kit is the only pledge level that includes a Compute Module pre-loaded with a PantaHub software stack. The aluminum case is only available for sale as a kit.

Kit includes:

• Aluminum/plastic enclosure
• Raspberry Pi Compute Module 3 - pre-loaded with PantaHub software stack
• Two antennas
• Powered by Raspberry Pi logo

LimeNET Micro with Acrylic Kit

The acrylic case is custom-designed to keep your LimeNET Micro safe. And the kit is made to give you all the components you need to get started right out of the box.

Full kit includes:

• Acrylic enclosure
• Raspberry Pi Compute Module 3
• Heatsink for the CM3
• Fan
• Two antennas

Antennas

We’re offering omni-directional antennas with SMA connectors, optimized for frequency ranges of 800-960 MHz, 1710-2170 MHz, and 2400-2700 MHz. These are the same antennas used with the LimeSDR-USB and the LimeSDR Mini.

GPS Antenna

The antenna offered during the campaign has a 3 M cable with an SMA connector and a 28 dB gain.

Adapter for Classic Raspberry Pi

A small SO-DIMM form factor board plus ribbon cable to enable use of a classic/consumer Raspberry Pi with the LimeNET Micro.

Free & Open Source

As with the LimeSDR family, the LimeNET Micro is a free and open source project. We will be releasing code, firmware, schematics, layout, and associated project files via MyriadRF shortly.

Lime Suite

The LimeNET Micro uses the same host-side software as previous LimeNET integrated systems, called Lime Suite. Lime Suite is entirely open source and supports a variety of software-defined radios and APIs. You can learn more about Lime Suite at its GitHub repository and MyriadRF project page.

PantaHub

PantaHub lets you connect your devices and transform them into bare-metal infrastructure. Designed for deeply embedded and high-grade enterprise systems alike, the Pantavisor device agent and PantaHub are the perfect choice for the management of Linux devices and their firmware lifecycles.

The PantaHub base image will be pre-loaded onto all Compute Modules included in the Aluminum Kit pledge levels.

Comparison Table

* - Maximum 10 MHz receive-only or 5 MHz full-duplex transmit plus receive. Actual RF bandwidth and sample rate will vary depending on any DSP or other processing also taking place on the Raspberry Pi Compute Module 3(L).

Risks & Challenges

As in the previous Lime Microsystems campaigns, the supply chain is the biggest risk — parts shortages could delay production. However, since the critical parts we’re using in LimeNET Micro are the same as those in the LimeSDR and LimeSDR Mini, the Micro will benefit from the considerable work we’ve already put into creating the LimeSDR supply chain.

Shipping & Fulfillment

All orders will be shipped from Crowd Supply’s warehouse in the United States. For a product of this scale, maintaining a separate fulfillment operation in Europe is not economically feasible and would actually increase the overall cost to the end customer. You can find out more about Crowd Supply’s shipping fulfillment in their Guide.

Support & Documentation

If you have a question about ordering, paying, or shipping, please refer to The Crowd Supply Guide.

If you have a technical question about the operation of the LimeNET Micro or any of its applications, please ask your question on the Myriad-RF forum.